1. Field
The present disclosure is directed towards antennas and in particular to phased array antennas. Still more particularly, the present disclosure relates to an active electrically scanning phased array antenna.
2. Background
A phased array is a group of antennas in which the relative phases of the respective signals feeding the antennas are varied in such a way that the effective radiation pattern of the array is reinforced in a desired direction and suppressed in undesired directions. A beam pointing in a transmit phased array antenna is achieved by controlling the phase and timing of the transmitted signal from each antenna element in the array. The combined individual radiated signals combine to form the constructive and destructive interference patterns of the array. A phased array may be used to point a fixed beam, or to scan the beam rapidly in azimuth or elevation.
One type of phased array antenna is a wide scanning Q-band phased array antenna. This type of antenna may be used to facilitate communications among land, sea, and air-based mobile platforms and fixed ground locations, typically via satellite. In one example, a wide scanning Q-band phased array antenna may be used on an ocean-going vessel, such as a submarine, to transmit communications signals to the Milstar satellite constellation. In designing this type of antenna, many antenna elements are required to be placed in a grid pattern with a pitch of approximately one-half of the wave length.
The resulting element size for this type of antenna may be on the same order as the size of monolithic microwave integrated circuit (MMIC) chips used for signal processing and amplification. These types of requirements push the boundaries of hermitic microelectronic packaging and create problems for heat dissipation or removal. Further, the high frequency needed for the microwave signals also increases the challenge in distributing a microwave signal to all elements without incurring excessive loss.
Therefore, it would be advantageous to have an improved phased array antenna architecture.